diff --git a/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt b/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt new file mode 100644 index 0000000000000000000000000000000000000000..e893615ef63570a4fdf4f04b2d4f1cd95ac81279 --- /dev/null +++ b/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt @@ -0,0 +1,26 @@ +Broadcom BCM2835 VideoCore mailbox IPC + +Required properties: + +- compatible: Should be "brcm,bcm2835-mbox" +- reg: Specifies base physical address and size of the registers +- interrupts: The interrupt number + See bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt +- #mbox-cells: Specifies the number of cells needed to encode a mailbox + channel. The value shall be 0, since there is only one + mailbox channel implemented by the device. + +Example: + +mailbox: mailbox@7e00b800 { + compatible = "brcm,bcm2835-mbox"; + reg = <0x7e00b880 0x40>; + interrupts = <0 1>; + #mbox-cells = <0>; +}; + +firmware: firmware { + compatible = "raspberrypi,firmware"; + mboxes = <&mailbox>; + #power-domain-cells = <1>; +}; diff --git a/Documentation/devicetree/bindings/mailbox/mailbox.txt b/Documentation/devicetree/bindings/mailbox/mailbox.txt index 1a2cd3d266db0b59a5709bccecef737f9aadf139..be05b9746c693c5cd595bfdd48411d143a18f1c5 100644 --- a/Documentation/devicetree/bindings/mailbox/mailbox.txt +++ b/Documentation/devicetree/bindings/mailbox/mailbox.txt @@ -22,17 +22,11 @@ Required property: - mboxes: List of phandle and mailbox channel specifiers. Optional property: -- mbox-names: List of identifier strings for each mailbox channel - required by the client. The use of this property - is discouraged in favor of using index in list of - 'mboxes' while requesting a mailbox. Instead the - platforms may define channel indices, in DT headers, - to something legible. +- mbox-names: List of identifier strings for each mailbox channel. Example: pwr_cntrl: power { ... mbox-names = "pwr-ctrl", "rpc"; - mboxes = <&mailbox 0 - &mailbox 1>; + mboxes = <&mailbox 0 &mailbox 1>; }; diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index 84b0a2d74d60b7b1761fd2be9632aa28869d06a2..e269f084497dc5a531bdccc58563ed95e53fdbdb 100644 --- a/drivers/mailbox/Kconfig +++ b/drivers/mailbox/Kconfig @@ -56,8 +56,18 @@ config PCC config ALTERA_MBOX tristate "Altera Mailbox" + depends on HAS_IOMEM help An implementation of the Altera Mailbox soft core. It is used to send message between processors. Say Y here if you want to use the Altera mailbox support. + +config BCM2835_MBOX + tristate "BCM2835 Mailbox" + depends on ARCH_BCM2835 + help + An implementation of the BCM2385 Mailbox. It is used to invoke + the services of the Videocore. Say Y here if you want to use the + BCM2835 Mailbox. + endif diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile index b18201e97e2988b5d0b451807c00c01094d6a8e5..8e6d82218a09422d7849e5e83dbd19324e593763 100644 --- a/drivers/mailbox/Makefile +++ b/drivers/mailbox/Makefile @@ -11,3 +11,5 @@ obj-$(CONFIG_OMAP2PLUS_MBOX) += omap-mailbox.o obj-$(CONFIG_PCC) += pcc.o obj-$(CONFIG_ALTERA_MBOX) += mailbox-altera.o + +obj-$(CONFIG_BCM2835_MBOX) += bcm2835-mailbox.o diff --git a/drivers/mailbox/arm_mhu.c b/drivers/mailbox/arm_mhu.c index ac693c63535769442aba9a452947850f88c8016f..d9e99f981aa98ee229a40517d7fa86a14533d886 100644 --- a/drivers/mailbox/arm_mhu.c +++ b/drivers/mailbox/arm_mhu.c @@ -110,7 +110,7 @@ static void mhu_shutdown(struct mbox_chan *chan) free_irq(mlink->irq, chan); } -static struct mbox_chan_ops mhu_ops = { +static const struct mbox_chan_ops mhu_ops = { .send_data = mhu_send_data, .startup = mhu_startup, .shutdown = mhu_shutdown, diff --git a/drivers/mailbox/bcm2835-mailbox.c b/drivers/mailbox/bcm2835-mailbox.c new file mode 100644 index 0000000000000000000000000000000000000000..0b47dd42f3bdbd37fab111bc726e0de3464b31f3 --- /dev/null +++ b/drivers/mailbox/bcm2835-mailbox.c @@ -0,0 +1,217 @@ +/* + * Copyright (C) 2010,2015 Broadcom + * Copyright (C) 2013-2014 Lubomir Rintel + * Copyright (C) 2013 Craig McGeachie + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This device provides a mechanism for writing to the mailboxes, + * that are shared between the ARM and the VideoCore processor + * + * Parts of the driver are based on: + * - arch/arm/mach-bcm2708/vcio.c file written by Gray Girling that was + * obtained from branch "rpi-3.6.y" of git://github.com/raspberrypi/ + * linux.git + * - drivers/mailbox/bcm2835-ipc.c by Lubomir Rintel at + * https://github.com/hackerspace/rpi-linux/blob/lr-raspberry-pi/drivers/ + * mailbox/bcm2835-ipc.c + * - documentation available on the following web site: + * https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Mailboxes */ +#define ARM_0_MAIL0 0x00 +#define ARM_0_MAIL1 0x20 + +/* + * Mailbox registers. We basically only support mailbox 0 & 1. We + * deliver to the VC in mailbox 1, it delivers to us in mailbox 0. See + * BCM2835-ARM-Peripherals.pdf section 1.3 for an explanation about + * the placement of memory barriers. + */ +#define MAIL0_RD (ARM_0_MAIL0 + 0x00) +#define MAIL0_POL (ARM_0_MAIL0 + 0x10) +#define MAIL0_STA (ARM_0_MAIL0 + 0x18) +#define MAIL0_CNF (ARM_0_MAIL0 + 0x1C) +#define MAIL1_WRT (ARM_0_MAIL1 + 0x00) +#define MAIL1_STA (ARM_0_MAIL1 + 0x18) + +/* Status register: FIFO state. */ +#define ARM_MS_FULL BIT(31) +#define ARM_MS_EMPTY BIT(30) + +/* Configuration register: Enable interrupts. */ +#define ARM_MC_IHAVEDATAIRQEN BIT(0) + +struct bcm2835_mbox { + void __iomem *regs; + spinlock_t lock; + struct mbox_controller controller; +}; + +static struct bcm2835_mbox *bcm2835_link_mbox(struct mbox_chan *link) +{ + return container_of(link->mbox, struct bcm2835_mbox, controller); +} + +static irqreturn_t bcm2835_mbox_irq(int irq, void *dev_id) +{ + struct bcm2835_mbox *mbox = dev_id; + struct device *dev = mbox->controller.dev; + struct mbox_chan *link = &mbox->controller.chans[0]; + + while (!(readl(mbox->regs + MAIL0_STA) & ARM_MS_EMPTY)) { + u32 msg = readl(mbox->regs + MAIL0_RD); + dev_dbg(dev, "Reply 0x%08X\n", msg); + mbox_chan_received_data(link, &msg); + } + return IRQ_HANDLED; +} + +static int bcm2835_send_data(struct mbox_chan *link, void *data) +{ + struct bcm2835_mbox *mbox = bcm2835_link_mbox(link); + u32 msg = *(u32 *)data; + + spin_lock(&mbox->lock); + writel(msg, mbox->regs + MAIL1_WRT); + dev_dbg(mbox->controller.dev, "Request 0x%08X\n", msg); + spin_unlock(&mbox->lock); + return 0; +} + +static int bcm2835_startup(struct mbox_chan *link) +{ + struct bcm2835_mbox *mbox = bcm2835_link_mbox(link); + + /* Enable the interrupt on data reception */ + writel(ARM_MC_IHAVEDATAIRQEN, mbox->regs + MAIL0_CNF); + + return 0; +} + +static void bcm2835_shutdown(struct mbox_chan *link) +{ + struct bcm2835_mbox *mbox = bcm2835_link_mbox(link); + + writel(0, mbox->regs + MAIL0_CNF); +} + +static bool bcm2835_last_tx_done(struct mbox_chan *link) +{ + struct bcm2835_mbox *mbox = bcm2835_link_mbox(link); + bool ret; + + spin_lock(&mbox->lock); + ret = !(readl(mbox->regs + MAIL1_STA) & ARM_MS_FULL); + spin_unlock(&mbox->lock); + return ret; +} + +static const struct mbox_chan_ops bcm2835_mbox_chan_ops = { + .send_data = bcm2835_send_data, + .startup = bcm2835_startup, + .shutdown = bcm2835_shutdown, + .last_tx_done = bcm2835_last_tx_done +}; + +static struct mbox_chan *bcm2835_mbox_index_xlate(struct mbox_controller *mbox, + const struct of_phandle_args *sp) +{ + if (sp->args_count != 0) + return NULL; + + return &mbox->chans[0]; +} + +static int bcm2835_mbox_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + int ret = 0; + struct resource *iomem; + struct bcm2835_mbox *mbox; + + mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL); + if (mbox == NULL) + return -ENOMEM; + spin_lock_init(&mbox->lock); + + ret = devm_request_irq(dev, irq_of_parse_and_map(dev->of_node, 0), + bcm2835_mbox_irq, 0, dev_name(dev), mbox); + if (ret) { + dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n", + ret); + return -ENODEV; + } + + iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mbox->regs = devm_ioremap_resource(&pdev->dev, iomem); + if (IS_ERR(mbox->regs)) { + ret = PTR_ERR(mbox->regs); + dev_err(&pdev->dev, "Failed to remap mailbox regs: %d\n", ret); + return ret; + } + + mbox->controller.txdone_poll = true; + mbox->controller.txpoll_period = 5; + mbox->controller.ops = &bcm2835_mbox_chan_ops; + mbox->controller.of_xlate = &bcm2835_mbox_index_xlate; + mbox->controller.dev = dev; + mbox->controller.num_chans = 1; + mbox->controller.chans = devm_kzalloc(dev, + sizeof(*mbox->controller.chans), GFP_KERNEL); + if (!mbox->controller.chans) + return -ENOMEM; + + ret = mbox_controller_register(&mbox->controller); + if (ret) + return ret; + + platform_set_drvdata(pdev, mbox); + dev_info(dev, "mailbox enabled\n"); + + return ret; +} + +static int bcm2835_mbox_remove(struct platform_device *pdev) +{ + struct bcm2835_mbox *mbox = platform_get_drvdata(pdev); + mbox_controller_unregister(&mbox->controller); + return 0; +} + +static const struct of_device_id bcm2835_mbox_of_match[] = { + { .compatible = "brcm,bcm2835-mbox", }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm2835_mbox_of_match); + +static struct platform_driver bcm2835_mbox_driver = { + .driver = { + .name = "bcm2835-mbox", + .owner = THIS_MODULE, + .of_match_table = bcm2835_mbox_of_match, + }, + .probe = bcm2835_mbox_probe, + .remove = bcm2835_mbox_remove, +}; +module_platform_driver(bcm2835_mbox_driver); + +MODULE_AUTHOR("Lubomir Rintel "); +MODULE_DESCRIPTION("BCM2835 mailbox IPC driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/mailbox/mailbox-altera.c b/drivers/mailbox/mailbox-altera.c index a266265677d3ebf533290a01a1a0af6212f2e292..bb682c926b0a048ab1918ba13a89c140dff19d96 100644 --- a/drivers/mailbox/mailbox-altera.c +++ b/drivers/mailbox/mailbox-altera.c @@ -285,7 +285,7 @@ static void altera_mbox_shutdown(struct mbox_chan *chan) } } -static struct mbox_chan_ops altera_mbox_ops = { +static const struct mbox_chan_ops altera_mbox_ops = { .send_data = altera_mbox_send_data, .startup = altera_mbox_startup, .shutdown = altera_mbox_shutdown, diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c index 19b491d2964f313744513920803e1c327305d7f9..c7fdb57fd166cbf9cb8a0035c56f67a75ff8aa0a 100644 --- a/drivers/mailbox/mailbox.c +++ b/drivers/mailbox/mailbox.c @@ -318,7 +318,7 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index) return ERR_PTR(-ENODEV); } - chan = NULL; + chan = ERR_PTR(-EPROBE_DEFER); list_for_each_entry(mbox, &mbox_cons, node) if (mbox->dev->of_node == spec.np) { chan = mbox->of_xlate(mbox, &spec); @@ -327,7 +327,12 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index) of_node_put(spec.np); - if (!chan || chan->cl || !try_module_get(mbox->dev->driver->owner)) { + if (IS_ERR(chan)) { + mutex_unlock(&con_mutex); + return chan; + } + + if (chan->cl || !try_module_get(mbox->dev->driver->owner)) { dev_dbg(dev, "%s: mailbox not free\n", __func__); mutex_unlock(&con_mutex); return ERR_PTR(-EBUSY); @@ -357,6 +362,35 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index) } EXPORT_SYMBOL_GPL(mbox_request_channel); +struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl, + const char *name) +{ + struct device_node *np = cl->dev->of_node; + struct property *prop; + const char *mbox_name; + int index = 0; + + if (!np) { + dev_err(cl->dev, "%s() currently only supports DT\n", __func__); + return ERR_PTR(-ENOSYS); + } + + if (!of_get_property(np, "mbox-names", NULL)) { + dev_err(cl->dev, + "%s() requires an \"mbox-names\" property\n", __func__); + return ERR_PTR(-ENOSYS); + } + + of_property_for_each_string(np, "mbox-names", prop, mbox_name) { + if (!strncmp(name, mbox_name, strlen(name))) + break; + index++; + } + + return mbox_request_channel(cl, index); +} +EXPORT_SYMBOL_GPL(mbox_request_channel_byname); + /** * mbox_free_channel - The client relinquishes control of a mailbox * channel by this call. @@ -390,7 +424,7 @@ of_mbox_index_xlate(struct mbox_controller *mbox, int ind = sp->args[0]; if (ind >= mbox->num_chans) - return NULL; + return ERR_PTR(-EINVAL); return &mbox->chans[ind]; } diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c index 0f332c178b07a049d3153887b57643659ed2487b..a3dbfd9c647994ec6794701cfc25a327739640ad 100644 --- a/drivers/mailbox/omap-mailbox.c +++ b/drivers/mailbox/omap-mailbox.c @@ -604,7 +604,7 @@ static int omap_mbox_chan_send_data(struct mbox_chan *chan, void *data) return ret; } -static struct mbox_chan_ops omap_mbox_chan_ops = { +static const struct mbox_chan_ops omap_mbox_chan_ops = { .startup = omap_mbox_chan_startup, .send_data = omap_mbox_chan_send_data, .shutdown = omap_mbox_chan_shutdown, @@ -639,18 +639,18 @@ static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller, mdev = container_of(controller, struct omap_mbox_device, controller); if (WARN_ON(!mdev)) - return NULL; + return ERR_PTR(-EINVAL); node = of_find_node_by_phandle(phandle); if (!node) { pr_err("%s: could not find node phandle 0x%x\n", __func__, phandle); - return NULL; + return ERR_PTR(-ENODEV); } mbox = omap_mbox_device_find(mdev, node->name); of_node_put(node); - return mbox ? mbox->chan : NULL; + return mbox ? mbox->chan : ERR_PTR(-ENOENT); } static int omap_mbox_probe(struct platform_device *pdev) diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index 7e91d68a3ac3d02b2622315b2745f605c5961300..26d121d1d501b7617857a364a63c9dd4b97c1438 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -198,7 +198,7 @@ static int pcc_send_data(struct mbox_chan *chan, void *data) return 0; } -static struct mbox_chan_ops pcc_chan_ops = { +static const struct mbox_chan_ops pcc_chan_ops = { .send_data = pcc_send_data, }; diff --git a/include/linux/mailbox_client.h b/include/linux/mailbox_client.h index 1726ccbd8009a814564dd717000288733c759ff5..44348710953f277576975b1bfe37375fc50e899c 100644 --- a/include/linux/mailbox_client.h +++ b/include/linux/mailbox_client.h @@ -40,6 +40,8 @@ struct mbox_client { void (*tx_done)(struct mbox_client *cl, void *mssg, int r); }; +struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl, + const char *name); struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index); int mbox_send_message(struct mbox_chan *chan, void *mssg); void mbox_client_txdone(struct mbox_chan *chan, int r); /* atomic */ diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h index d4cf96f07cfc42452f7bafb1d546cf64b984319e..68c42454439be372caba99424ef6a57bac5f5c2d 100644 --- a/include/linux/mailbox_controller.h +++ b/include/linux/mailbox_controller.h @@ -72,7 +72,7 @@ struct mbox_chan_ops { */ struct mbox_controller { struct device *dev; - struct mbox_chan_ops *ops; + const struct mbox_chan_ops *ops; struct mbox_chan *chans; int num_chans; bool txdone_irq;